import java.util.Scanner;

public class java01 {
    public static void main(String[] args) {
        final double PI=3.1415927;
        Scanner sc=new Scanner(System.in);
        System.out.println("请输入球体半径：");
        int a=sc.nextInt();
        double v=(a*a*a*PI)*4/3;
        System.out.println("球体体积为："+v);
    }
}